Piston ring



July 31, 1945., c. F. ENGELHARDT f 2,380,421

' PISTON RING Filed Nov. 8, 1943 therethrough.

Patented July 31, 1945 Carl'F. Engelliardt, Yeadon. Pm, "liner to Wilkening Manufacturing Company, Phlladel phia, Pa.

Original application May 19, 1942, Serial No. V 443,601. Divided'and this application Novemher 8, 1943, Serial No." 509,353

,9 Claims. kcl. sea-4s) H a provide a piston-ring formed of a single helical The present invention relates to certain new relates more particularly to oil-control piston rings adapted for use in internal combustion engines.

The present application is a division of my I goo-pending application Serial No. 443.601. filed May 19, 1942.

and useful improvements ,in piston rings and it strip of sheet metal .or the-like having two com- 1 plots turns. The helical strip is provided with An object of the present invention is to pro vide a simple inexpe'nsive and eilicient piston:

ring for use in internal combustion engines. An

other object of the present invention is to pros vide apiston-ring formed of a strip offsheet metal or the like suitably bent and folded to provide an inter-locked composite structure having continuous. axially-separated cylinder-contacting ribs and having oil-drain passages Other objects and ilcation, appended I claims and accompanying drawing. I

For the purpose of illustrating the invention,

there are shown inithe .accompanying drawing .forms thereof which are' at present preferred.

since the same have been found in practice to give satisfactory and reliable results, although it is to be'understood that the various instrumentalities of which the invention consists can be'variously arranged and organized and that the invention is not limited to the precise arrangements and organizations of; the instrumentalities as herein shown and described. r

, Referring to the accompanying drawing in which like reference characters indicate like reference parts throughout:

Figure 1 represents a perspective view .of'one embodiment of the present inventionxas ,itappears when dis-assembled tended; f I

I igure 2 represents a fragmentary edge eleva-v advantag'esof the present invention are apparentin'the following speci andhelically ex 7 alternating upper segments ii and lower segments. 4! extending in generally horizontal axially-displaced planes. Successive segments 4i and are connected by generally axially-' extending portions N which are formed integrally with, and at obtuse angles to. the horizontally-extending segments Ii and 42.

The axially-extending portions "-0 of one complete turn '(as for example the upper turn shown in Figure 1) of the strip 40 are'cut out .as at along their inner peripheral edges for slightly more-than half the radial dimension. The axially-extending portions 43-h I of the other. turn (as for example the lower turn shown in Figure l) of the strip 40 are out out thereof.

as at along their outer peripheral edges for slightly more than .half the radial dimension thereof.

' shown in Figure 1. when its free'ends 41. and are spread axially apart. Whenever, however.

the free ends 4! and 48 are-released, the natural.

tional view of the embodiment ofl igurel; showing the zone of cross-over? forming the iuncture of the upper and lower turns of. thehelix as it appears when the ring is assembled.

Figure 3 represents a cross-sectionalviewgenerallyalongthe line 3-4 of Figure 2Jshowing theappearance of the piston-ring wheninstalled I upon a piston.

"Figure 4 represents a cross-sectional view gen-.

" l ng the line 4-4 ofFigure 2. I a

Figure 5 represents a cross-sectional view generally similar to that of Figure 4. but -sliowing a modified form of the present invention.-

. In the embodiment ofvli gures lto 4. I may together.

' The horizontal cross-over segment I! integrall'y connects the two turns of the strip 40 and I has one axially-extending portion II-q cut out along the inner peripheral edge as at and the other axiallyextending portion ll-b out out along the outer peripheral edge as at ll; the segment 48 thereby effecting the transition from the construction of one turn to the construction of the other turn of the member 40.

assumes the helical form The member 40 resiliency of the member "causes it to spring Figures}.- 3 and -.That- -is,.the axially-extend ing' portions'l Ib of thelower turn fit within the cut-out edges of the portions "-4 while "the portions "-6 fit withinv the cut-out edges 1' ll of the portions "-42. shown in Figure .2, the'portions "-11 and 48-h are oppositely in-. clined'in the inter-nested position of the member 40. s

In the assembled 3 and 4.. the upper segments of the upper and lower turns are. in alternatingjiuxtaposition and.

similarly, the lower segments of the upper and lower turns are in alternating .iuxtaliolltidnm Provide a pan-of axially-displaced'more or less continuous cylinder contacting ribs.

If the cross-over segment II is then 7 pressed radially inwardly, the upper, and lower turns willdove-tail within each'other to provide the generally closed construction shown in position shown in l'lgu're's .3. r

intermediate the cylinder-contacting ribs and are defined by the upper and lower horizontal" segments 4! and 42 and the radially-spaced axially-extending portions 43a and 43-b.

The free ends 41 and 48 may be seated against each other in any suitable manner as for example in the manner shown in Figure 2 wherein the free ends are placedradially adjacent to each other and terminate axially adjacent the crossover segment 48.

The fold-lines separating the segments from the axially-extending portions are preferably formed as sharp edges by coining or other suitable operations whereby the adjacent segments will make firm and continuous contact with each other. as shown particularly in Figure 2 to provide a generally fluid-tight seal therebetween. -;Wh en the piston-ring is assembled within the groove 34 of a piston 35 and is installed within a cylinder 38 as shown in Figure 3, the piston-ring: is "compressed slightly both radially and circumi'erentially; the ring having inherent resiliency whereby it will tend to expand radially and circumierentially against the cylinder wall and to make firm contact therewith without the us of a separate expander spring. i

The radially-adjacent axially-extending portions 43a and 43-b have a slight clearance 89 radially therebetween whereby the upper and lower turns are free to move axially and radially of. each other to a limited extent, thereby to permit the piston-ring better to conform to any I irregularities in the cylinder wall such as might assembled. it makes contact with the cylinder wall only along'the axially-spaced. more or less continuous, annular ribs formed by the juxtaposed upper and lower segments. I

This embodiment may. in some respects. be

preferred since the contact area between the piston and the cylinder is reduced. thus giving a greater unit pressure to reduce blow-by and, a

the same time, to reduce wear.

The present invention may be embodied in other specific iorms without departing from the spirit or essential attributes thereof, and it is therefore desired that the present embodiments be conentially distributed radially-extending oil-pasageways.

2. A piston-ring comprising a helical strip of ribbon-like sheet metal having at least two complete turns, said strip being axially non-sinuously corrugated to provide successive plane segments disposed alternately in axially-separated radial planes and radially-reduced generally axiallyextending interconnecting portions formed integrally with said segments, the interconnecting portions of one turn of said stripbelng' radiallydisplaced from the interconnecting portions oi the other turn of said strip, said strip being disposedin axially-collapsed radially-nested position with the interconnecting portions of the respective turns being radially juxtaposed in intercrossing relationship.

3. A piston-ring comprising a helical strip of ribbon-likesheet metal having at least two complete turns, said strip being axially non-sinuously corrugated to provide successive plane segments disposed alternately in axially-separated 'radial planes and radially-reduced generally axially extending connecting portions oi one turn' of said strip being radially-displaced from the interconnecting portions of the other turn of said strip, said strip being disposed in axially-collapsed radiallynested position with the interconnecting portions of'the respective turns being radially, juxtaposed in intercrossing relationship, the plane segments of the respective turns being arranged in altemating juxtaposition to provide a pair of more or less continuous annular axially-separated cylinder-contacting ribs.

4. A piston-ring comprising a helical strip [of ribbon-like sheet metal having at least two c m-' plete turns, said strip being axially non-sinuously corrugated to provide successive plane cylinder contacting lands disposed alternately in axiallyseparated radial planes, and generally axiallyextending interconnecting portions formed integrally-with said lands, the interconnecting portions of one turn of said strip being radially spaced apart from the interconnecting portions of the other turn, said strip being disposed in axially-collapsed radially-nested position, thereby to provide a pair of more or less continuous annular axially-separated cylinder-contacting ribs having oil-passageways therebetween.

5. A'piston-ring comprising a helical strip or ribbon-like sheet metal having at least two complete turns, said strip being axially non-,fllnuously i corrugated to provide successive plane cylindercontacting' lands disposed alternately in axially separated radial planes, and generally axiallysidered in all respects as illustrative and not rc- 1 strictive. reference being had to the appended claims rather than to the foregoing description to indicate the scope of the invention.

extending interconnecting portions formed integrally with said lands, the interconnecting portions of one of said turns being disposed adiacent the outer edge or the piston-ring and the Having thus described the invention, what is be sointerconnecting portions or: the other of said turns being disposed adjacent the inner edge-of the, piston-ring, said strip being disposed in axially-collapsed radially-nested position. thereby to provide a pair of more or'le'ss continuous annular axially-separated cylinder-contacting ribs having oil-passageways therebetween.

6. A piston-ring comprising a helical strip of ribbon-like sheet metal having at least two complete turns, said strip being axially non-sinuously corrugated-to provide successive plane cylindercontacting lands disposed alternately in axiallyseparated radial planes, and generally axially extending interconnecting portions formed integrally with said lands, the interconnecting por- 'plete turns, said strip being axially non-sinuously tions of one 01' said turns being disposedadiacent the outer edge of the piston-ring and the.

interconnecting portions of the other of said turns being disposed adjacent the inner edge of the piston-ring, the interconnecting portionsof the first-mentioned turn being recessed somewhat irom the outer edges ofalong their outer edges the lands, said strip be g disposed in axiallycollapsed radially-nested Jposition, thereby to provide a pair of more or less continuous annular axially-separated cylinder-contacting ribs having oil-passageways therebetween.

corrugated to provide successive plane segments disposed alternately in axially-separated radial planes and generally axially-extending interconnecting portions formed integrally with said segment's, said strip being disposed in axially-col- 7. Apiston-ring comprising a helical strip of L ribbon-like sheet metal having at least two com,-

plete turns, said strip being axially non-sinuously corrugated to provide successive plane cylindercontacting lands disposed alternately in axiallyseparated radial planes, and generally axiallyextending interconnecting portions formed integrally with said lands, the interconnecting portions ofone of said turns being disposed adjacent the outer edge of the piston-ring and the interconnecting portions or the other of said turns being disposed adjacent the inner edgeof the piston-ring, the interconnecting portions of the first-mentioned turn having their outer edges recessed somewhat from the outer edges of the lands and having their inner edges recessed somewhat from the outer edges of the interconnect? ing portions of the other turn, said strip being disposed in axially-collapsed radially-nested position,thereby to provide a pair of more or less continuous annular axially-separated cylinder contacting ribs .having oil-passageways therebetween. t

- -8. A piston-ring comprising a helical strip of ribbon-like sheet metal having at least two comcent the outer edge of the piston-ring and the lapsed radially-nested positio with the interconnecting portions of each t tercrossing relationship to provide circumferentialiy distributed radially-extending oil-passageways, said strip having a double-length plane segment intermediate successive turns.

9. A piston-ring comprising a helical strip of ribbon-like sheet metal having at least twocomplete turns, saidstrip being axially non-sinuousiy corrugated to provide successive plane cylindercontacting lands disposed alternately in axiallyseparated radial planes, and generally axially extending interconnecting portions formed integrally with said lands, theinterconnectingportions of one of said turns being disposed adja-h interconnecting portions of the other of said turns being disposed adjacent the inner edge of "the piston-ring, the interconnecting portions of the first-mentioned tum being recessed somewhat along their outer edges from the outer edges of the lands, said strip being disposed in axiallyaidally separated cylinder-contacting ribs having oil-passageways therebetween, said strip having a. double-length plane cylinder-contacting land intermediate successive turns whereby the upper J and lower lands of one turn are circumferentially displacedirom the eorrespondinig lands or the other tum. CARL F. ENGEIHARDT.

disposed in in-' 

